How can you move the cursor authomatically among different GUI components in a JFrame

Thread view:

Fereshteh Shojaei - 19 Jan 2004 19:12 GMT

Hi,

I wonder if somebody can help me. I would like to move the cursor from one
JTextField to another one when I press <CR>.
Regards,
fereshteh

Reply to this Message

Andrew Thompson - 19 Jan 2004 21:39 GMT

....

| I wonder if somebody can help me. I would like to move the cursor from one
| JTextField to another one when I press <CR>.

A FocusTraversalPolicy should be able to
do that for you..

--
Andrew Thompson
* http://www.PhySci.org/ PhySci software suite
* http://www.1point1C.org/ 1.1C - Superluminal!
* http://www.AThompson.info/andrew/ personal site

Reply to this Message

Andrew Thompson - 19 Jan 2004 21:42 GMT

| ....I would like to move the cursor from one
| JTextField to another one when I press <CR>.

Oops! I was thinking of going around the
components in a 'non-standard' way, you
need to implement a KeyListener and add it
to each JTextField, then on KeyEvent, check
if it is the <cr> key..

--
Andrew Thompson
* http://www.PhySci.org/ PhySci software suite
* http://www.1point1C.org/ 1.1C - Superluminal!
* http://www.AThompson.info/andrew/ personal site

Reply to this Message

Jon A. Cruz - 20 Jan 2004 01:08 GMT

> Hi,
>
> I wonder if somebody can help me. I would like to move the cursor from one
> JTextField to another one when I press <CR>.

Try adding an ActionListener to the JTextField.

It's always best to minimize hooking keystrokes directly.

Reply to this Message

Andrew Thompson - 20 Jan 2004 01:30 GMT

| > ..I would like to move the cursor from one
| > JTextField to another one when I press <CR>.
|
| Try adding an ActionListener to the JTextField.

Huh! It had never occured to me that
would work!*

| It's always best to minimize hooking keystrokes directly.

Why?

* well, for the sake of the OP..
(and because I had invested an entire
2 minutes of my life checking what
Jon said)
__________________________
import java.awt.*;
import java.awt.event.*;

public class KeyboardText extends Frame implements ActionListener
{
TextField tf1 = new TextField(),
tf2 = new TextField();

KeyboardText()
{
super("KeyBoard Text");

setLayout(new GridLayout(0,1));

tf1.addActionListener(this);
add( tf1 );

tf2.addActionListener(this);
add( tf2 );

pack();
setVisible(true);
}

public void actionPerformed( ActionEvent ae )
{
System.out.println(ae);
if (ae.getSource()==tf1) tf2.requestFocus();
else tf1.requestFocus();
}

public static void main(String args[])
{
new KeyboardText();
}
}
__________________________

--
Andrew Thompson
* http://www.PhySci.org/ PhySci software suite
* http://www.1point1C.org/ 1.1C - Superluminal!
* http://www.AThompson.info/andrew/ personal site

Reply to this Message

Jon A. Cruz - 20 Jan 2004 02:27 GMT

> | It's always best to minimize hooking keystrokes directly.
>
> Why?

To keep things higher-level, encapsulated and robust.

If you go mucking about with keys directly you might:

* mess up keys that are used by the windowing system
* use keys that are not accessible or easy on keyboards in other countries
* use keys that don't match the defaults for all other applications on
the target platform (Ctrl-C versus Command-C on the Mac, for example)
* interfere with accesibility software/systems
* make your program hard to internationalize
* interfere with other widget/frame combinations
* confuse users

Those are just what I could list in about 30 seconds. I'm sure there are
a lot more.

It's similar to avoiding hooking mouse events directly. Easy to forget
to call MouseEvent.isPopupTrigger() when needed, etc.

Reply to this Message

Andrew Thompson - 20 Jan 2004 02:59 GMT

"Jon A. Cruz" wrote in message

| > | It's always best to minimize hooking keystrokes directly.

....

| To keep things higher-level, encapsulated and robust.

<snip list>

..hmmm. Makes me wonder just how
workable my Calculator is on other systems.
http://www.physci.org/launcher.jsp#Calculator

I'll have to check it out further..

--
Andrew Thompson
* http://www.PhySci.org/ PhySci software suite
* http://www.1point1C.org/ 1.1C - Superluminal!
* http://www.AThompson.info/andrew/ personal site

Reply to this Message

Jim Sculley - 21 Jan 2004 02:17 GMT

> "Jon A. Cruz" wrote in message
> | > | It's always best to minimize hooking keystrokes directly.
[quoted text clipped - 7 lines]
>
> I'll have to check it out further..

Be sure to explore InputMap and ActionMap. These are the preferred
methods for binding keystrokes to actions.

Jim S.

Reply to this Message

Andrew Thompson - 21 Jan 2004 02:30 GMT

"Jim Sculley" writ..

| > "Jon A. Cruz" wrote in message
| > | > | It's always best to minimize hooking keystrokes directly.

....

| Be sure to explore InputMap and ActionMap. These are the preferred
| methods for binding keystrokes to actions.

Thanks Jim, I'll look into it.

Reply to this Message

How can you move the cursor authomatically among different GUI components in a JFrame

Free Magazines